Mandrel



Aug. 8, 1933. w. M. ROBINSON I 1,921,584

MANDREL Filed July 6, 1931 2 Sheets-Sheet 1 Aug. 8, 1933. w. M. ROBINSON I ,9

MANDREL Filed July 6, 1931 2 Sheets-Sheet 2 v FIG. I l.

Patented Aug. 8, 1933 UNITED STATES PATENT OFFICE MANDREL Ward Robinson, Port Huron, Mich., assignor to Mueller Brass 00., Port Huron, Mich., a Corporation of Michigan Application July 6, 1931. Serial No. 548,937

2 Claims.

0 one other piece being removable from the mandrel assembly to permit removal of the piece accomplishing the deformation; the provision of a. mandrel of the class described which is particularly applicable for the manufacture of pipe fittings from seamless tubing; and the provision of a mandrel of the class described which is simple and economical in construction and operation. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts, which will be exemplified in the structures, products and processes hereinafter described, andthe scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which are illustrated several of various possible embodiments of the invention,

Fig. 1 is an elevation of a finished fitting formed by the methodsherein set forth;

Fig. 2 is a side elevation of a length of tubing from which the fitting of Fig. 1 is formed, also showing a mandrel inserted therein;

Fig. 3 is an end elevation of the tubing and mandrel of Fig. 2;

Fig. 4 is an exploded view of the mandrel of Figs. 2 and 3;

Fig. 5 is a vertical cross section of the tubing and mandrel of Fig. 2 after being subjected to an upsetting operation; and also showing dies in cross section;

Fig. 6 is an end elevation of the set up of Fig. 5;

Fig. 7 is an elevation of a fitting after the upsetting operations have been completed;

Fig. 8 is a view similar to Fig. '7 but showing the top of a side outlet of Fig. 7 cut off;

Fig. 9 is an elevation of a fitting or stamping after it has been'upset positioned in forming jaws for spinning, said jaws also being shown in cross section;

Fig. 10 is a view similar to Fig. 9, but showing a spinning tool inserted;

Fig. 11 is a view similar toFig. 10 but showing smaller in diameter than the outlets 3 and 5. 7

:troduced in the holes 11 and which flows around the grooves 9 and spreads by capillary action beside outlet such as 7, it was necessary to start the fitting after the spinning. operation has been completed; and,

Fig. 12 is a composite view summarizing the various steps in the formation of the fitting 01' Fig. 1 from alength of tubing.

Similar reference characters indicate corre sponding parts throughout the several viewsof the drawings.

Referring now more particularly to Fig. 1, there is shown at numeral 1 a T-fitting adapted to be used. to join conduits, such as are used in gas, electric or plumbing work or the like. The fitting 1 has main outlets 3 and 5, and a side outlet 7 which, as shown in Fig. 1, is slightly The fitting 1 is preferably formed to comply with principles set forth in the United States patent to Hill Number 1,770,852, the patent to Mueller Number 1,801,171, and the patent to Gresley Number 1,776,502. The fitting is provided with grooves 9, and the holes 11, and is adapted to receive conduit in its receiving portions, hold the conduit thus received by means of sealing material intween the entering conduit and the receiving portions as described in the said aforementioned patents.

Fittings of the class shown in Fig. 1, are often made by casting the metal. They have also been made from ductile tubing. However, the fittings made from tubing although cheaper than those made from casting had the disadvantage that in order-to obtain enough metal for an integral with relatively thick walled tubes which ran up the cost. of the fitting because of the amount of metal consumed. The present invention overcomes the former difiiculty of obtaining a sufiiciency of metal for the integral side outlet, and accordingly provides an improved method for making fittings from tubing.

Briefly the invention comprises starting with a tube having a diameter and thickness of wall which is greater than the diameter and thickness of wall of the final fitting, and which has a length shorter than the length of the final fitting, upsetting all but a portion of said tubing to reduce said tubing in diameter, elongate the end sections to a point where there is no excess metal and so reduce thethickness of the walls of said tubing to that of. the walls of the final fitting, and drawing and/or swedging and/or spinning the portion of the tubing not upset to form an inte- 11o off, the ragged edges ofthe end are removed, and the ends are belled by either spinning or machining, and the solder distribution grooves 9 and holes 11 are properly position in the fitting as shown in Fig. 1.

In Figs. 2 through 11, the detailed steps of the operation of the fabrication of the fitting is shown. In Fig. 2, a tube 13 having a relatively thick wall 15 and anoriginal internal diameter x, is shown with a mandrel 17 positioned therein. The ends of the mandrel 17 extend appreciably beyond the relatively short piece of tubing 13. As shown in Fig. 3, the mandrel is made up of, or comprises four pieces which fit together at faced surfaces 27. The pieces comprise a top piece 19, two identical side pieces 21 and 23 and a bottom piece 25, all engaging each other at the aforementioned surfaces 27. For the main part, the assembled mandrel 17 is in the shape of a cylinder, but has a bump or bulge 29 formed at the center and on the top. More specifically the pieces 19, 21 and 23 of the mandrel carrying the bump portion, and the way in which the mandrel pieces are put together, and the way in which the bump 29 is formed is clearly shown in Fig. 4.

. After the mandrel 17 is thus positioned in the tube 13, the whole is now placed in an upsetting machine and either solid or split dies 31 axially forced toward each other (and toward the center of the mandrel 17) from each end of the tubing 13. The dies 31 individually have an inner profile analogous to the outer profile of half the length of the built-up mandrel 17. The walls of the dies 31 are, however, sufficiently spaced from those of the mandrel to allow the proper thickness of the wall 15 to remain between the mandrel and the die. Thus as the dies 31 are forced toward each other the tubing 13 is upset and appreciably elongated as well as having its thickness substantially reduced. The portion of the dies 31 comparable to the bump portion 29 of the mandrel 17 are spaced above the mandrel or bulge 29 a distance equal to the thickness of the tubing 13 and consequently this portion of the tubing 13 as indicated by numeral 33 retains its original thickness as shown at numeral 15.

The dies 31 are now removed from the tubing 13 leaving it tightly covering the shape of the mandrel 17. It is clear that the mandrel 17 cannot be removed at once and as a wholeassembly from the fitting or tubing 13, inasmuch as the bulge 29, interlocking with the corresponding bulge 33 of the tubing'13, would prevent such a removal. Consequently the bottom piece 25 of the mandrel 17 is first removed, then the two side pieces 21 and 23 are knocked down and respectively removed and then the top piece 19 is dropped to the bottom of the tubing 13 and removed.

The tubing 13 in this condition has been materially reduced in diameter, and has had the thickness of its wall reduced, whereby the whole length of the tubing 13 has been materially lengthened, but the original thickness of the walls of the portion 33 has been retained.

It is now necessary to anneal the tubing 13 if it has become cold work hardened to the extent that further cold working of the metal is difiicult.

The tubing 13 is then subjected to a second operation which is a repetition of the first operation but which employs a mandrel 17 having a diameter which is smaller than the diameter of the first mandrel 17 but which has a bump 29 having along dimension equal to the original 1 diameter a:.u Accordingly the diameter and the thickness of the tube 13 is still further reduced in all portions except the portion 33. It is thus seen that the original diameter x of the tubing 13 is retained as the internal vertical height of the top of the bulge 33 and that the original thickness of the tubing is retained atthe bulge 33.

This operation of upsetting the tubing 13, with its attendant annealing may be performed from one to six or more times, depending upon "the material and the amount of deformation required.

In Fig. 7, the tubing 13 is shown reduced in diameter and thickness to the desired dimensions, and the top 35 of the bump 33 is cut off to provide the fitting as shown in Fig. 8, and furthermore the ends of the fitting are properly trimmed. The fitting as shown in Fig. 8 is now ready for the proper finishing operation to remove any ragged portions and also to bell the ends and either spin or machine the grooves 9 into the fitting. At this time the holes 11 may also be provided in the receiving portions 3, 5 and 7.

After one or two upsetting operations, an alternative method of proceeding with the fabrication of the fitting as shown in Fig. 1 is to switch to a hydraulic or press work to elongate the bump by means of expanding the bulge 33 with hydraulic press work into a die. Also such a bump 33 as elongated by hydraulic press work, may be further shaped by performing a hole 39 in the top of the bulge 33, placing the fitting between forming jaws 43, inserting a shaping tool 41 in said hole and spinning said jaws to spin said metal. This is the known process of spinning and during this process one or two annealing operations may be required before the requisite deformation is completed. Figs. 10 and 11 show the beginning and end of the spinning operation.

Referring now to Fig. 12 the complete fabrication of the fitting 1 by three upsetting'operations and two spinning operations is shown; thus at index a the original blank is shown, at b the blank after the first upsetting operation, 0 is the blank after the second upsetting operation, and at d the blank after the third upsetting operation. Although only three upsetting operations are shown any necessary number may be employed. Likewise a hydraulic press work operations may also be employed to expedite the fabrication. The end' of the first spinning operation is shown at index e, the second and final spinning operation at index I, which last operation completes the fitting for the trimming and finishing work as hereinbefore described.

.An advantage of the method of the invention as herein described, is that the integral side outlet of the fitting formed is provided with the same thickness as the rest of the tubing forming the fitting.

Another advantage of the invention is that fittings may now be formed from tubing and at a much lower cost than fittings can be formed by casting the metal into the form of the fitting.

It is to be understood that by providing the mandrel 17 with a plurality of oppositely disposed bulges 29, and properly assembling the same, that cross or other shaped fittings having more than three outlets may be fabricated.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A mandrel for upsetting operations comprising a plurality of segments fitting together to form an assembly of generally cylindrical contour, at least one of said segments having a regular cylindrical surface, and at least one other of said segments having a protrusion on its otherwise cylindrical surface, said segments being so constructed that, upon removal of said segment having a regular surface from the assembly, said segment having the protrusion thereon may be moved into such position that it is entirely within the confines of the regular cylindrical contour of the assembly.

-first segment from the assembly,

second and fourth segments being substantially the same but opposite, the relative size of said segments being such that, upon removal of said I said second, third and fourth segments may successively be moved into such position that the portion of the protrusion thereon is entirely within the confines of the regular cylindrical contour of the assembly,

WARD ROBINSON. 

